Fiber lasers are known as a kind of solid-state laser. Such a fiber laser has a variety of advantages such as good process quality due to its fine light emitting point, good usability, and good maintainability due to its capacity to use a semiconductor laser as an excitation light source. In response to recent demands for a high output-power fiber laser, excitation light of high intensity may be introduced into the fiber. However, there is limitation on the increase in the output power of the excitation light emitted from a single light emitting point of the semiconductor laser used as the excitation light source. One proposed solution to the above involves the collection of light beams emitted from a plurality of light emitting points into the fiber (Refer to Patent Literature 1).